Capsule forming die roll



Dec. 21, 1954 F. E. STIRN ETAL 2,697,317

CAPSULE FORMING DIE ROLL Filed Dec. 18, 1953 8 Sheets-Sheet 1 F. i J- ATTORNEY Dec. 21, 1954 F. E. STIRN ETAL 2,697,

CAPSULE FORMING DIE ROLL Filed Dec. 18. 1953 8 Sheets-Sheet 2 RI Hi ra M WhehF ATTORNEY Dec. 21, 1954 F. E. STIRN ETAL CAPSULE FORMING DIE ROLL 8 Sheets-Sheet 3 Filed Dec. 18, 1953 nmwue .5. 741 1 01?,

Dec. 21, 1954 F. E. STIRN ETAL CAPSULE FORMING DIE ROLL 8 Sheets-Sheet 4 Filed Dec. 18, 1,953

INVENTORS rmwwr z. .STMN 4927/04 5 rm zafi ATTORNEY F. E. STIRN ETAL CAPSULE FORMING DIE ROLL Dec. 21, 1954 8 Sheets-Sheet 5 Filed Dec. 18, 1953 INVE F/Pfl/VA r J 4277/0/1 J. 7:4

ATTORNEY Dec. 21, 1954 F. E. STIRN ETAL 2,697,317

CAPSULE FORMING DIE ROLL Filed Dec. 18, 1953 8 Sheets-Sheet 6 INVENTORS ATTORN EY 8 Sheets-Sheet 7 Dec. 21, 1954 F. E. STIRN ETAL CAPSULE FORMING DIE ROLL Filed Dec. 18, 1953 Fig. 2|.

INVENTORS Frank E. Stirn Arthur S. Taylor BY M M JTTORNEY Dec. 21, 1954 F. E. STIRN ETAL CAPSULE FORMING DIE ROLL 8 Sheets-Sheet 8 Filed Dec. 18, 1953 INVIIVTORS Frank E. Shrn Arthur S. Taylor 8 2 .m F mm MW 11 TTOR NE) United States Patent CAPSULE FURMING DIE ROLL Frank E. .Srtirn, Pearl River, and Arthur S. Taylor, Spring Valley, N. Y., assignors to American Cyanamid Company, New York, N. Y., a corporation of Maine Application December 18, 1953, Serial No. 399,130

25 tClaims. (Cl. 5389.5)

This invention relates to improvements in a method and a mechanism for forming and filling capsules from deformable strip materials, such as soft gelatin, which capsules may be filled with a powder and a liquid simultaneously, or the powder alone; and which capsules are formed of a symmetrical configuration by an essentially asymmetric process, and to elements of such mechanism and method, particularly a die roll.

This application is a continuation-in-part of our copending applications, Serial No. 16,554, filed March 23 1948, entitled Method and Machine for Making Capsules, Patent No. 2,663,128, dated December 22, 1953, and Serial No. 164,426, filed May 26, 1950, entitled Method and Apparatus for Forming Combination- Filled Capsules. Certain related subject matter is disclosed in our applications No. 189,913, filed October 13, 1950, entitled Heating Die Rolls, and Serial No. 193,946, filed November 3, 1950, entitled Vacuum trip Retention.

it is object of this invention to provide a method, and a machine for practicing the method, whereby a powder is filled into a charge chamber in a measuring roll and therein compacted, held, and retained by vacuum, and transferred from such chamber into a deformable strip material lined cavity in a die roll, to which a liquid may be added before or after the powder is transferred thereto. The lined cavity containing the powder charge with any desired associated quantity of liquid is then covered by a second strip of a deformable strip material, and the two portions fastened together and joined by a pressure seal caused by cutting out the two strips simultaneously, thereby forming a capsule with a flat top. The thus formed capsule is then ejected from the forming cavity and permitted to assume a desired shape.

it is an object of this invention to provide a coater, whereby either or both sides of the strip material may be coated with the same or different materials; and to provide a system where either or both strips may be so coated.

It is an additional object of this invention to provide a cavity die roll which is convenient to assemble, accurate in operation, and has a long life in production.

it is a still further object of this invention to provide a liquid feed method whereby a liquid is fed at a substantially uniform rate into the capsule-forming mechanism, and because it is fed at a uniform rate, and the capsules are formed at a uniform rate, a uniform charge of the liquid is fed into and enclosed in each capsule without the inconvenience of measuring every charge to every capsule.

It is a yet further object of this invention to provide a means whereby powder measuring roll charge chambers may be kept clean by the use of gas jets and a vacuum system, so that any powder which may remain in the chambers is removed and ejected without the dust thereby raised escaping into the filling room.

It is yet a further object of this invention to provide a means whereby the capsules, as ejected from the cavities in the cavity die wheel in which they are formed, are uniformly and completely ejected without being allowed to be retained in the gelatin web which is residual, or without being allowed to be kept in the cavities too long; and upon being ejected, are picked up by an air conveyor system, whereby they are transferred rapidly and uniformly to any desired location, and which system has the further advantage of serving as a test of the strength of the seal, because of the comparatively turbulent transportation of the capsules.

A particular object of this invention is to provide a means and a method where a single machine is provided which will permit the formation of symmetric capsules, which capsules may contain both a powder and a liquid in any desired proportion, and the filling of which is independently controlled. In the past, it has been customary to fill capsules with a liquid or a paste, i. e., a liquid in which solid particles are suspended; and it has been necessary to have sufficient of the liquid present so that the paste could be pumped and handled as a liquid, rather than as a solid. By this, our invention, we have found that it is possible to handle the two separately, and fill the powder individually into the cavities in such quantities as my be desired, independent of the amount of liquid which is being filled.

Also, in the past, it has been considered necessary that each cavity receive its own charge of liquid by an individual action of a pump, whereby each capsule cavity has a certain volume of a liquid resulting from the ejection by positive displacement into the cavity as such. We have found that by having a series of capsuleforming cavities, each lined with the capsule shell material, passing at a substantially uniform rate, underneath and adjacent to a liquid-filling nozzle, and by having the liquid discharged through the nozzle at a constant rate, the liquid will fill uniformly into the individual capsule-forming cavities, and that the charges retained therein will be extremely consistent and well within conventional tolerances. As strange as it seems, the uniformity of charges attained by this method is at least as great as that attained by the individual measurement of the charges for the individual capsules.

In the past, capsules of this nature have been formed almost exclusively from soft gelatin, a plasticized mixture of gelatin, glycerin, and water, together with such coloring, flavoring, and odors as may be desired. We have found that our machine and method work satisfactorily if the gelatin strip is plasticized with a polyethyleneoxide, in addition, to or instead of, the glycerin; and we have found that various gelatin substitutes may be used in conjunction with the machine. Whereas the machine at present has its greatest commercial utility in the formation of gelatin capsules, as raw materials fluctuate in price, the use of gelatin substitutes rather than gelatin itself is an economic problem, and our machine is adapted for the use of such substitutes. Because the commercial demand today requires pharmaceutical capsules of gelatin rather than a substitute for the gelatin, our machine will be described in connection with the use of gelatin films for which todays markets find the greatest demand; but it is to be understood that other strip materials may be used, when, as, and if the market and price considerations render them economically expedient.

It is a further advantage of our machine that means are provided whereby the interior of the capsule may be coated with a protective material to protect the gelatin from the contents of the capsule, or the contents of the capsule from the gelatin, if desired. Such protection is sometimes necessary when the contents of the capsule are of a highly hygroscopic nature, and the moisture in the capsule gelatin would otherwise have a deleterious effect upon the hygroscopic powder contained.

Of course, if materials other than gelatin are used, the dispersing medium may be other than water, and under such circumstances, depending upon the contents of the capsule, different materials may be necessary to protect the various portions from each other.

Additionally, the entire operation can be carried out in an inert atmosphere as, for example, nitrogen, if the moisture or the oxygen of the normal atmosphere would have a deleterious influence on the contents of the capsule. These, and other objects of the invention will be apparent from the description in detail appearing in the following specification and in the accompanying drawings, which set forth by way of example certain embodiments of the invention covered by our appended claims.

Figure 1 is a side elevation of substantially the entire capsule filling machine. The deformable strip forming hemispherical ends.

means is not shown in this figure, as such is not part of the present invention.

Figure 2 is a elevation view in detail of a cavity die roll, showing the valve plates in connection therewith.

Figure 3 is a sectional view through the cavity die roll, showing certain features of its construction, and its relationship with the valve plates.

Figure 4 is an enlarged portion of both the cavity die roll and the powder measuring roll, showing their operation at the point of fill.

Figure 5 is a partial sectional view of the cavity die roll and the sealing roll, showing the action occurring at the point where the cover strip is placed over the capsule cavity and the capsule is cut out and formed.

Figure 6 is a sectional view of a portion of the cavity die roll at the point where the capsules are ejected, showing the action which there occurs.

Figure 7 is a surface view of a portion of the cavity die roll, showing the arrangement of the various cavities on the surface of the roll and certain of the details of the capsule cavity inserts, the capsule ejecter plugs, and the capsule ejector manifolds.

Figure 8 is a section view showing a portion of a powder measuring roll and the associated cleaning jet system.

Figure 9 is a view showing the cleaner jet system Which faces the powder measuring roll, viewed from the position of the powder measuring roll.

Figure 10 shows the cleaning jet system, assembled to the powder measuring roll.

Figure 11 shows the face of the cavity die roll valve plate. 7

Figure 12 shows a side elevation of the cavity die roll valve plate.

Figure 13 shows a m dification of the machine in which the powder measuring roll is of a different size than the cavity die roll, and shows two diiferent liquid feeding nozzles which may be used individually or in cooperation to feed at least one liquid into the individual chambers.

Figure 14 is a view of the surface of a cavity die roll in a modification in which comparatively short oval capsules are formed and with but a single capsule ejector plug.

Figure 15 is a view of the surface of the cavity die roll in another modification showing round capsule cavities with a single capsule ejector plug.

Figure 16 is a view of an air conveyor system for transferring the capsules, after their ejection, to a desired location.

Figure 17 is a front view of a cavity die roll and stator, showing the pressure and vacuum chests, heat control, etc., of a modification of the machine.

Figure 18 is a front View of the stator of the machine of Figure 17. Figure 19 is a side view of the stator of Figures 17 and 18.

Figure 20 is a detail of a capsule cavity insert for long oval capsules in a die roll.

Figure 21 is a detail of a capsule cavity roll insert for long oval capsules showing an insert retaining screw.

Figure 22 is a detail of a capsule cavity roll insert for a short oval capsule, showing a single ejector plug.

Figure 23 shows a capsule cavity insert for elliptical capsules having a single ejector plug and a hollow capsule cavity insert retaining screw.

Figure 24 shows a capsule cavity insert for spherical capsules with a single ejector plug.

Figure 25 is a capsule cavity insert for spherical capsules showing a foraminous bottom plug even with the bottom of the capsule forming cavity.

Figure. 26 shows a capsule cavity insert for spherical capsules with a foraminous bottom plug with said plug in a lower position.

Figure 27 is a capsule cavity insert for forming spherical capsules showing a hollow cavity insert retaining screw, with a foraminous bottom plug therein.

Figure 28 is a detail of a capsule cavity insert assembly for forming spherical capsules in an apparatus such as is shown in Figures 17, 18 and 19.

The size and shape of the completed capsule are a matter within the discretion of the designer. The cap- .sules may be round, elliptical, or may be the so-called long oval, which consists of a cylindrical portion with two This latter shape is one which in the past has been the most difficult to form, and one which 4 is most useful, because the diameter, taken crosswise is a minimum for the contents, so that a comparatively large capsule volume is contained 'in a capsule which may be swallowed, as the diameter of the capsule, rather than its length, determines the ease with which it may be swallowed. Because in the past, the greatest difliculty has been found in trying to get the so-called long ovals to come out without bends, bows, or unsymmetrical configurations, and because a description of such a long oval machine will explain how, with a minimum of adaptation, other shapes may be formed, the long oval machine will be described in detail and its adaptations into other forms and shapes such as shown in Figures 14 and 15 will be readily understood by those skilled in the art without detailed descriptions.

Whereas the machine may be used with any plastic material the strips of which will seal to each other when out with a blunt-edged cutter, we shall describe the machine particularly in conjunction with a soft gelatin composition, such as is currently desired for therapeutic pur poses. The machine, as described here in detail, is perfectly satisfactory for the preparation of multi-vitarnin compositions particularly those in which such vitamins as vitamin A and vitamin D are used in combination with such as thiamin, riboflavin, niacinamide, calcium pantothenate, pyridoxine, ascorbic acid, folic acid and/ or other materials. Of these, vitamin A and vitamin D are most easily handled in an oily solution, and the others are usually most easily handled in a powdered form. In the machine herein described, the vitamin A and vitamin D, etc. may be incorporated in an oil. The solid constituents may be combined aspowdered materials and added as a fine impalpable powder, thereby forming a combination capsule in which each individual capsule has present the desired quantities of both a powder and a liquid. It is to be understood that if desired, the liquid portion may be so small as to be negligible or may be completely omitted without its interfering with the formation of the capsules and their powdered contents. In this connection, it may be mentioned that air filled capsules may be easily formed by our machines and, normally are formed during the starting operation, in which the gelatin sheets are first fed into the machine flat, and then the vacuum applied, thereby causing the formation of empty capsules with nothing but air in them; then the oil is adjusted, and then the powder adjusted, thus giving the final form of filled capsule with all of the desired ingredients. The concentration of the medicament in the oil or powder fill may be adjusted with a diluent so that the capsule is completely filled, or the capsule may be partially filled, leaving air in the remainder, whereby uniform sized capsules may be formed with any desired variation in therapeutic contents. With this brief summary of its method of operation, we shall now proceed to describe in detail, in connection with the drawings, the construction and a method of operation of a particular embodiment of our invention.

The machine will be described with the parts in the order in which they act upon the gelatin film.

Coater The lower film 21, as shown in Figure 1, is fed from the left and over the oiler roll 22 The oil roll is, in turn, kept oiled with its contact with an oil feed roll 23, which rotates partially submerged in an oil bath 24. A standard form of constant level device may be used to maintain the oil at a constant level and, depending upon level and viscosity, the rate of feed may be varied. For normal operating purposes, a mineral oil, such as is designed for therapeutic purposes, may be used. If tie oil is too thick, it may be thinned with a solvent such as lig'roin, to insure that its viscosity is as desired. After passing over the oiler roll, the film passes under positioning roll 25 and to an inside coating roll 26, which inside coatingroll, in turn contacts an inside coating feed roll 27, which inside coating feed roll rotates partially submerged and in inside coating trough 28. This inside coating trough may be kept filled to a constant liquid level by a constant level feed device.

Normally. the inside coating is one which is designed to protect the film and the capsule contents from each other. With gelatin films and vitamins, this coating may consist of a gum or shellac, such as confectioners lac, or gum sandarac. gum mastic, or other substantially water-proof gum. The solvents may be such as chloroform, ether, carbon tetrachloride or a mixture, or it may be a petroleuin base, such as petroleum and ether, or ligroin. The liquid level and dilution may be varied to change the thickness of the deposited coating, or additional transfer rolls used. If the contents of the capsule are to be innocuous material, these rollers may be disconnected and the uncoated gelatin film fed to the machine.

For thin films it is usually desirable that all of the strip contacting rolls be power driven to avoid stresses in the film. Any conventional drive means, not shown, may be used to turn these rolls so the surface speed is the same as the desired rate of strip travel at the point.

The film next contacts the cavity die roll.

Cavity die roll One modification of the cavity die roll itself 29 may be seen in relationship with the other parts of the machine in Figure 1, and enlarged views, Figures 2 and 3. Certain details of the roll and its mode of operation may be more clearly seen in Figures 4, 5, and 6.

The die roll itself may be of integral or built-up construction. In the particular modification shown in Figures 1, 2 and 3, the cavity die roll consists of a cavity die roll blank 30, which is machined from a single piece of material. This blank has a hub with an opening for an axle with a suitable means such as a keyway 31a for fastening the cavity die roll itself upon the shaft. Set screws or other fastening means may be used; or the wheel may be permitted to turn upon this shaft if driven by a suitable means. The cavity die roll has, around its periphery, a series of capsule cavity inserts 31, which fit into insert slots 32 cut in the surface of the cavity die roll blank. Underneath the capsule cavity inserts, at the bottom of the insert slots is at least one capsule ejector plug 33, which has integral therewith a capsule ejector piston 34, which piston fits in the capsule ejector piston cylinder 35, called the piston cylinder. One end of the piston cylinder is connected by a manifold 36 to the valve seat surface 37 of the cavity die roll blank. Adjacent to this valve seat surface is the valve plate 38.

In more detail, capsule cavity inserts 31 are shaped something like a bathtub in general configuration. They have a cutting rim 39 as shown in Figures 6 and 7 which consists of two semi-cylindrical end portions connected by straight portions, and a bottom 40. The capsule cavity inserts are individually formed. The rim thickness may be approximately that of the film upon which they work. From /2 to 1 /2 times the film thickness is a useful operating range. The depth of each of the capsule cavity inserts may be such that the periphery around the capsule as formed in the insert is approximately the same as around the end of the capsule cavity insert, and the thickness of the bottom is preferably considerably greater for rigidity but may be varied depending upon the materials of construction. The dimensions are not critical, and may vary over wide limits, depending upon the size and shape of capsules desired.

Through the bottom of the capsule cavity inserts, there are holes of sufiicient size to hold the capsule ejector plugs 33. The portion of the plug which extends into the capsule cavity insert may be of such length that it will extend to at least approximately the top of the capsule cavity insert when in raised position. In manufacture, the capsule cavity inserts are cut to have a greater depth than that finally desired, and may be out from rectangular stock. They may be of a tool steel, or other hard material, so as to give a superior life to the finished cavity die roll. The insert slots should be slightly smaller than the size of the outside of the capsule cavity inserts, so that they may be pressed therein and firmly retained through the life of the cavity die roll. Other retaining means may be used but unduly complicate the problem of construction. At the bottom of the slot, before inserting the capsule cavity insert, is cut the capsule ejection piston cylinder. It may be seen that the relative spacing on this is comparatively important for final assembly. The depth of this cylinder is such that the piston which slides therein is concentric with the end of the capsule ejector plug, and will slide so that in its lower position, the top of the plug is approximately level with the bottom of the cavity insert; and at the top of its stroke, the end of the plug is near the top of the cavity as shown in Figure 6. Beneath each piston there is a manifold passage 36 connected to the valve seat surface 37, as shown in Figure 3 and elsewhere. The bottom of the capsule ejector piston should have a slot or serration therein, so that it does not seat against the top of this manifold passage in the '6 bottom of the piston and form an airtight seal; the slot, of course, may be in the bottom of the cylinder rather than in the piston itself.

In construction, it is most convenient to first form the cavity die roll blank with all of the insert slots; then into each piston cylinder drop the piston and plug, then press in the capsule cavity insert. After the complete series of inserts are assembled, the surface of the cavity die roll may be ground so that each cutting out rim 39 is cut to the same height, and as part of the cylindrical surface of the roll. Accuracy is required in the construction, because the cutout of the individual capsules is by this rim being forced against the seal rolls, and variations in radius may give a defective cut-out.

The piston should fit loosely in its cylinder, and the plug should fit loosely in the hole at the bottom of the capsule cavity insert, so that the vacuum which operates through the manifold can act past the piston, past the plug, and upon the gelatin strip which is on the surface of the cavity die roll. It is very important that this clearance be sufiicient that the vacuum can act upon the gelatin strip and leave sufiicient clearance to prevent binding and to prevent any powder, etc. from clogging the mechanrsms.

In construction, an interference between at least parts of the capsule cavity insert and the insert slot in the neighborhood of from .002-.005" is very satisfactory when the cavity die roll blank is formed from a high grade brass or bronze and the inserts are formed from steel, either annealed or hardened. An adequate effect of vacuum can usually occur if there is clearance in the neighborhood of from .004.Ol0 around the piston and its cylinder, and between the plug and the hole in the bottom of the insert in which it slides.

1f the insert slot is slightly longer than the cavity insert, the holding action on the sides is sufficient to retain the assembly in position. A slight leakage around the outside of the cavity inserts may even be an advantage if the strip is wide enough to lap over the ends of the cutting out rims, and contact the roll surface proper, as then the vacuum can act on the strip between the inserts, and more firmly retain it in position.

The valve plate 38 slides upon the valve seat surface of the cavity die roll. As shown in Figure 3, there is a valve plate on each side of the particular rolls here shown. These are symmetrical and their function the same. All cavities could be manifolded to a single side, if desired. One of these valve plates is shown in Figures 11 and 12. These slide on the hub of the cavity die roll blank and against the face of the cavity die roll valve surface. Springs may be used to aid in positioning these plates, but normally the vacuum used during the operation of the machine is sutficient to hold these plates tightly against the surface of the cavity die roll valve seat surfaces.

As shown in Figure 2, two vacuum leads connect with the two vacuum chest portions of this plate. The vacuum connections are shown at 41 and 42, and the vacuum chests at 43 and 44, respectively. The vacuum chest 43 connects to a balancing chamber 46 so as to give a balanced action of the vacuum and to hold the plate smoothly against the surface of the cavity die roll throughout its entire periphery. The valve plate may be of molded plastic such as Micarta, or of metal. Portions of the plate may be cut away to cut down on the sliding areas to reduce friction.

The first chest 43 controls the ejector plugs and holds them down against the bottom of the cylinder throughout the top of the arc of the cavity die roll. There is a gap, as shown at 47, between the two vacuum chests, so that there is no vacuum acting on the strip at the time of formation of the seal, as will be described in detail later. At the ejector point there is a pressure chest 48 connected to a pressure line 49. As described later, the air pressure raises the plugs to the top of their travel, thereby ejecting the formed capsules, and causing their release from the cavity die roll. In operation, the valve plate is prevented from rotating by a valve plate positioning bracket 59. This bracket consists of an angle extending from the plate. It is anchored between two screws, 51 and 52, which act as a valve plate positioning screw upper and valve plate positioning screw lower, whereby the position of the valve plate may be micrometrically adjusted, so that the machine operates most etficiently.

In operation, the film, passing under the inside coating roll, next passes adjacent to, and rests upon the raised rims 'of the capsule cavity inserts. When the openings 7 of the manifold 36 come in contact with the vacuum chests 43, the vacuum pulls down the pistons, the plugs, and because of the loose fit, the entire film. Air pressure forces the gelatin film or strip down into the capsule cavity and the piston is drawn down against the bottom of its cylinder, so that the top of the plug is substantially Liquid Feed As the gelatin lined cavity revolves, it passes to the position shown at B, at which point it passes under the liquid feed nozzle 53. The liquid feed nozzle 53 is held in position by the nozzle positioning bracket 54. As shown in Figure 4, the nozzle itself does not contact the surface of the gelatin film, but is positioned at sufiicient distance therefrom so as to insure that no accidental contacts will occur. The nozzle may be placed well up into the bite of the roll, although this is not necessary. But it must feed at a point such that the liquid will not run out of the cavities. The liquid is fed through the liquid feed nozzle by a ptunp 55. This is a constant rate pump, which is designed to feed the liquid at a uniform rate. A gear pump is very satisfactory for this purpose. A separate pump and supply system is used for each row of cavities. It is desirable that an accurate gear pump, such as described in Patent 1,785,386 be used, so that the liquid will be fed at a uniform rate and any variations in viscosity, or other conditions, will not affect the rate of delivery of the pump.

The pump is best driven by the same drive means as is the rest of the machine, so that its rate of feed will be proportional to the rate of rotation of the cavity die roll. For flexibility this rate may be variable as, for example, by means of a positive infinitely variable drive system, so that the rate may be adjusted to that which is desired for a particular run of capsules, and after the initial adjustment remain the same and without change.

As shown in Figure 4, the liquid pumped by the pump 55, through the nozzle 53, is discharged as a solid, continuous stream into the capsule cavities as these gelatinlined cavities pass respectively underneath the nozzle. It is found that as no droplets are formed, the portion of the stream which passes into each cavity is the same, and

the portion which lies upon the top of the gelatin film,

between the cavities, has a tendency to flow into either the cavity preceding or the cavity following this raised portion; and in operation, the individual cavities have a substantially uniform charge.

It would appear that the gelatin cavities would contain different quantities of fluid by this type of operation. In the past, continuous machines have used a positive displacement so that each cavity will receive its own metered charge of fluid. We have found that this is totally unnecessary, and the much simpler, more effective procedures herewith described, are just as accurate, are far simpler, far more convenient, and far less susceptible to misadjustments or functional failure.

The partially liquid-filled capsule cavity passes, as shown in position C, forward up to position D. At position D, the solid contents of the capsule are placed in the gelatin-lined cavity containing the liquid. This occurs by the ejection of a powdered charge 56, from a charge chamber 57, in the powder measuring roll 58.

Powder Feed Substantially above the cavity die roll is located the powder measuring roll. The powder measuring roll 58 has a charge chamber 57 which cooperates with each of the capsule forming cavities in the cavity die roll. The roll may consist of a blank of approximately the same size as the cavity die roll, and rotates underneath a powder hopper 59, as shown in Figure 1. This powder hopper rides on the surface of the roll and has at its front a doctor, so that each of the chambers in the powder measuring roll is smoothed off uniformly filled as it passes from under the hopper. In the powder hopper, there may be a series of agitators 6i and if the hopper is deep, there may be a gas inlet 61, through which air, or an inert gas, is passed into the powder, so that the powder is agitated,

aerated, and kept loose and fluffy; otherwise, the powders may tend to cake at the bottom of the hopper.

As shown in Figure 4, the surface of this roll has formed in its surface a series. of charge chambers, each of which has such size and. configuration that its contents will be the desired charge of powder for one of the capsule cavities. At the bottom of the charge chamber, there are a series of filters 62, connected to a manifold 63. These charge chambers, as they pass under the hopper are connected to reduced pressure through the manifold whereby powder is uniformly compacted into the charge chambers by the operation of the reduced pressure. The charge is then smoothed oh? by the front of the hopper, acting as a doctor; and by the use of the vacuum, is held in position in the charge chamber as it passes around with the roll until it is above the capsule die roll. At this point, air or other gas is caused to act through the filter which discharges the powder charge into the individual capsule forming cavity. Normally speaking, the powder charge will remain compacted as such, although it may, inthe case of particularly free flowing powders break into a free powder during its release. The measuring roll valve plate 64 is similar in construction to the valve plate for the cavity die roll system, and it also has an angle bracket and positioning screws as shown in 65, as the positioning mechanism for the control of the exact point at which the powder is discharged.

Charge chamber cleaner Under some conditions, powder which is used may tend to cake, as for example, if cottonsed oil meal or other oiiy materials are used, and if permitted to cake, may tend to pack or aggregate in the charge chambers so that the charges will not be uniform. To prevent this, we found it desirable to equip the powder measuring roll with an air cleaner. As shown in Figures 8, 9 and 10, this cleaner consists of an air lance 66, which may be a small pipe having therein nozzle openings 67, which may be diagonally arranged, which may be positioned closely adjacent to the surface of the charge chambers and the powder measuring roll, so that the jets of air, or other gas are directed at such an angle into the powder measuring charge chamber as to hit tangentially at all portions of the chamber at some portion of its travel. These jets tend to loosen any powder which may aggregate and.

cause it to be dislodged and blown out of the charge chambers. The nozzle openings 67 may extend in any of various configurations to achieve this purpose, or a slot may be used. Certain configurations are as shown in Figures 8 and 9. To prevent particles of powder thus loosened from falling on to the web, or being discharged into the room, there is positioned about the air lance a vacuum shield 63. This shield is so positioned as to fit in close to the powder measuring roll, but without contacting it, so as to permit a minimum of leakage. At one end of this vacuum shield is a vacuum duct 69, which may lead to an ordinary household variety of vacuum cleaner or other source of vacuum, which so reduces the pressure within the vacuum shield that all powders and other loose particles are conveyed away from the surface of the wheel and into the vacuum system, where they may be then picked by a cleaner bag, powder separator, or other form'of device, or may be ejected to waste.

After the powdered charge is dropped into the indiv ual capsule-forming cavities, as shown at D in Figure 4, the combined charges rotate, as shown at E and F, during the course of which the powder may partially absorb the oil over to the position of the seal.

Seal roll The seal roll '75 is a substantially smooth surfaced roll, as shown in Figure 1. This roll is designed to have the same peripheral speed as the cavity die roll and be pressed against the surface thereof by springs 73. As shown in Fire 1, the axle of this roll has a bearing mounted at each end thereof, which bearing is held in position by a positioning rod 71, which has pressing against the ends thereof an equalizer oar 72 and positioning spring 73. This tends to hold the seal roll tightly against the surface of the cavity die roll and allows for any minor variations in diameter, or changes due to temperature, the yielding of various parts, etc., and permits a smooth uniform rolling contact at the'point of seal.

0n theseal roll, there may be placed a thermostat, as shown diagrammatically at 74, controlling internal heater elements, as shownldiagrammatically at 75, which in turn are connected through a slip ring system as shown diagrammatically at 76 to electrical lead 77. It is desired that the thermostat be adjustable, so that the temperature of the seal roll may be controlled as may be desired. It is desirable that two of the leads be power, and one be an indicator lead, so that an external means may be attached to show when the power is being supplied to the heat seal roll to increase the temperature. These controls are all conventional.

The seal roll 70 is normally operated so that it has a higher temperature than the remainder of the machine, whereby the cover strip 78 which may be coated by a mechanism similar to that shown for coating the lower strip, is fed over the seal roll 70 and by the seal roll fed towards the lower strip of gelatin containing the cavities. This action occurs as is shown diagrammatically in Figure 5.

Sealing action As shown at G in Figure 5, the filled capsule cavity having the powder and as much liquid as may be desired therein, approaches a junction point with the cover strip 78. If the liquid content is such as to permit some flow, the convergence of the strips will cause the fill to flow back into the capsule cavities.

As the filled cavity travels forward from the position shown at G to the position shown at H, the sealing cover strip approaches and completely covers the top of the cavity. If some air remains therein, no harm is done with normal constituents. If the constituents are sensitive to air, an inert gas may be used to blanket this portion of the machine so that the inert gas only is sealed into the capsule. If accurately adjusted for capsule contents, it is possible to operate so that there is substantially no free space within the capsule but this normally is not necessary.

The cover strip moves down against the capsule cavity as the two rolls approach the point of tangency or bite, and are brought into contact with each other, at which point the capsule contents are substantially then isolated; and as the roll continues to rotate towards the point of tangency, the cutting-out rim is forced upwardly through the two layers of strip material; and because of the soft characteristics of the material, cuts into them, effectively severing them completely. It is a characteristic of a gelatin film, and similar materials, when so cut, to unite with the adjacent film, thereby giving a uniform seal around the periphery of the capsule cavity, so that at the point shown at H, the leading edge of the capsule is completely sealed and the trailing edge substantially so. As the capsule, as it may now be called, approaches the point market I, and as the rolls separate, the residual web as shown at 79 may be separated from the formed capsule. The two portions of the strip in the web are usually united to each other around the periphery of the cutout.

For the separation of the capsules from the web, we have found it desirable to retain the capsules in their forming cavities and cause the web to be drawn against the surface of the sealing roll, and thus separate the two.

For best results in getting a uniform seal, and this is particularly important with the long oval type, the vacuum holding the strips which are forming the capsules should be released at the point of seal so that the only forces acting are the cutting out edges and the natural surface tension of the strip. If the vacuum is allowed to remain effective at this point, it may nonuniformly affect the gelatin, so that the capsules as formed are not as straight nor as symmetrical as is the case when the vacuum is released. The gap at 47 in the valve plates permits this release at the point of seal. To assist in separating the newly formed capsule from the strip, it is desirable that the vacuum be immediately reapplied, so as to cause the capsule to remain flat against the bottom of its forming die, while the residual web is removed and discarded. The initial separation is shown at I in Figure 5. As shown further in Figure l, the residual web may be run over an idler roll 80 and between take-off rolls 81, and then discarded. The take-oif rolls are preferably driven at a substantially higher surface speed than is the remainder of the mechanism, so that the web is stretched, assisting in causing the complete and smooth separation of the residual web from the capsules. The web from the take-off rollers may be run to discard or may be reworked to salvage the strip material.

The capsule forming cavities with the capsules held flat therein by vacuum move to the discharge pomt, as shown in Figure 6.

Capsule ejector system As shown in Figure l, the capsule ejector system consists of a shield 82, which may well be of a transparent material, enclosing a portion of the cavity die roll. As shown in Figure 6, the vacuum continues to operate through the manifold passages at this point; so that as shown at I, if the capsule is held against the bottom of the capsule die cavity by the vacuum, at K the vacuum is broken and the capsule permitted to attain a partially rounded shape by the action of the stresses within the gelatin film. As shown at L, air pressure from the pressure chest 48, operating under the piston, raises the plugs so that the surface of the plugs are approximately level with the top surface of the cavity die cutting edges, which forces the formed capsule outward and causes it to drop. If for any reasons the capsules tend to stick to the surface of the roll, there is a rotating stripper 83, which has blades of, for example, soft fabric travelling at a higher rate of speed than the surface speed of the cavity die roll, which strike the capsules and aid in releasing them. The capsules fall by gravity, aided by air flow, to the bottom part of the shield.

Pneumatic conveyor At the bottom of this shield, or the points to which the capsules would normally travel by gravity, there is shown a jet ejector system, consisting of a jet 84 near the center of a larger conveyor 85. Air under pressure operating through the jet ejector 84 causes the entire air system in the lower part of this shield to move in the direction of flow of the jet. The conveyor 85 is a larger diameter pipe, in which the jet causes air flow. To allow sutficient air, an air duct 86 provides a larger volume of air at a lower pressure to serve as a carrier. The jet 84 should have sufficient pressure so that all of the air in the shield tends to be drawn toward the conveyor duct 85, so as to prevent a raised pressure area, which would tend to blow the capsules out around any leaks. By having the entire system under reduced pressure, due to the jet 84, all capsules are drawn by the motion of air towards the lower portion of the shield and into the conveyor duct 85. The conveyor duct 85 may be a pipe with an elbow directed as desired, so that the capsules being carried by the air blast are caused to tumble and be agitated and moved at high speed in a desired direction. The tumbling action has a tendency to cause the capsules to become rounded and to break up any powder which may cake in the capsules, so that the skin stress will round the capsule to a symmetrical configuration. Also, the tumbling effect and the cooling and drying effect of the air blast permits the capsule surface to become slightly harder, so that it will not stick to adjacent capsules when discharged. Several jets may be used, or all of the air may feed through the ejector jet 84, if slightly constricted as in a Venturi tube.

We have found it convenient for this air conveyor to be discharged into either a drying pan or pill coating machine, whereby the capsules may be additionally tumbled as they are dried. The capsules, as they are dried, attain a comparatively hard, smooth coat, so that they may be packaged in accordance with standard pharmaceutical procedures. The treatment of the capsules from this point onward may be in accordance with conventional procedures, or as desired.

It is to be understood that the machine may be constructed so that it appears considerably different from that here shown without in effect varying from the scope of our invention. As shown in Figure 13, for example, the charge measuring wheel may be considerably smal er than the cavity die rolls provided, of course, that a cavity is adapted to pass under, and receive each charge from the charge roll at the point of transfer. Also as shown in Figure 13, the liquid may be filled into the capsule cavity either before or after the powder, or if desired, liquids may be fed in both locations so that two different liquids, as for example, two immiscible liquids, may be discharged into the cavities and filled into the capsules. This would permit two immiscible liquids and a powder each to be accurately measured into the individual capsules for consumption. If a smaller powder measuring roll is used, and a smaller sealing roll is used, the seal roll may be placed higher up around the periphery seed oil base.

of the cavity die roll, so that there is less tendency for the contents of the cavity to flow out. This is of particular interest if a comparatively large proportion of liquid is to be used.

With the exception of the gelatin web take-off rolls 80 and 81, all of the gelatin contact rolls are power driven and so connected that the surface speeds of all rolls is the same. If desired, the speeds of the various rolls may vary slightly because the plastic nature of the gelatin strip will take up minor variations. The gelatin to the roll may be stretched somewhat if desired, so as to alter the final shape of the capsules as a result of the residual stresses thereby induced. The seal'roll 70 may have vacuum ports to assist in positioning the gelatin film or may have slight depressions to relieve the surface opposite each cavity so as to provide room for slight relief of the capsule contents at the time of seal, as otherwise the cavity can be only partially filled, as room must be provided into which the covering layer may be displaced while the cutting edge is cutting out and severing the sheet portions forming the capsule. Such modifications cause complications in the timing of the rolls and are normally not used.

Operation In a room maintained at 6870 F. with relative humidity of 50%, a film of gelatin was cast which was approximately .031 thick as stripped from a casting roll. The outer surface of the lower strip of gelatin was coated with mineral oil. The upper strip was not coated, to prevent skidding on the seal roll. The inner surface of hot strips was coated with a solution of gum sandarac in chloroform. The gelatin film was passed over the surface of the cavity die roll and thereinto was placed an oil containing 1,000,000 units per gram of vitamin A and 50,000 units per gram of vitamin D in a predominantly cotton- A powdered charge containing for each capsule 6 milligrams of thiamin hydrochloride, 2 milligrams of riboflavin, 20 milligrams of niacinamide, 2 milligrams of calcium pantothenate, l milligram of pyridoxine hydrochloride, 150 milligrams of ascorbic acid and 5 milligrams of folic acid, was prepared. The oil feed pump was adjusted so that 10,000 units of vitamin A and 1,000 units of vitamin D in oil were placed in each cavity of the gelatin strip. The seal roll was adjusted to a temperature of 95 F. and the capsules were formed rapidly, uniformly,

and satisfactorily. The capsules were tumbled for half an hour in a tablet coating pan. After additional drying in trays in a room at a temperature of about 70 F. and a relative humidity of 35%, the capsules were found to be smooth, uniform and satisfactory.

Alternative die roll construction Modifications of the die roll may be used. For example, as shown in Figures 17, 18, 19 and 28, by suitable manifolding means the cavity die roll may be hollow, so that inside of the cavity die roll fits a die roll stator 88 containing a suction chest 88a in contact with the interior surface of the cavity die roll. Air is evacuated through the air ducts 127' in the cavity die roll during desired portions of the filling cycle. Air pressure acts through this duct during other portions of the cycle.

The stator 88, in which is located the suction roll chest 88a, has an integral part thereof manifolding means such that suction is applied over the required portion of the filling cycle. The suction is applied through a suction connection 89. Air pressure is applied through the air pressure lead 90 which applied pressure so that the ejector plugs are raised at the ejection point. A spring loaded sealing member 91 is used to separate the suction chest from the pressure chest, which member floats in the stator P so that any eccentricity or construction irregularities in the interior surface of the cavity die roll do not cause air leaks.

For temperature control of the cavity die roll it is convenient to install heating members in this stator, which may be of a high heat-conducting material such as brass. Heating element leads 93 are attached to electric heating elements in the interior of the stator. The current to these elements may be controlled by a thermostat 92.

-As is shown in Figure 17, the gelatin strip, after the cut-out of the capsules has occurred, may be retained adjacent to the cavity die roll until after the capsules have been ejected from the capsule forming cavities and transferred to the next step in the process.

It has usually been customary in capsule forming procedures to leave the capsules with the web and separating them as a distinct later step. However, by the present invention, it is found that by either retaining the capsules in the cavity die roll and stripping the residual web therefrom, as earlier mentioned and shown in Figures 1 and 5, or retaining the web against the cavity die roll until after the capsules have been removed as is shown in Figure 17, a more effective separation is obtained with fewer operations.

As disclosed and claimed in our co-pending application, now Patent No. 2,663,128, the temperature control of the die roll and its relationship with the temperature of the sealing roll is of great importance in the production of symmetrical capsules.

Figures 20 to 28 show the details of several different modifications of cavity die roll inserts which may be used. The selection of the cavity die roll inserts is based in part upon the desired form of the finished capsules and upon the machines that are available for constructing the die roll.

Figure 20 shows a long oval capsule cavity insert 930, in a cavity die roll 97. This capsule cavity insert is slightly longer than that shown in Figures 2 and 3, but the general construction is the same. The capsule cavity insert may be made of hardened steel and is placed in a slot 98 in the cavity die roll. Underneath this slot and as part of it are cylinders for the capsule ejector plugs 94 which have integral therewith a rim 95. The plug itself fits in a hole in the bottom of the capsule cavity insert with slight clearance for an air bleed. A slot 95 may be cut in the face of the rim so that the rim cannot seal against the bottom of the cylinder and prevent the flow of air. Underneath the assembly is an air duct $9 for the withdrawal or introduction of air as previously described. The top surface of the plug 94 is a fiat face 109, which is preferably approximately even with the bottom of the capsule cavity insert, when in the lowered position. The interior of the capsule cavity insert forms the capsule forming cavity 102. The top edge of the insert is the cutting-out rim 101. In construction it is preferable to make the insert slightly higher than is desired, and grind them off as a final operation to insure that they are all exactly the same height. These rims form a cylindrical surface which contacts the sealing roll as previously described.

Whereas it is convenient to make the slots 98 in the die roll slightly smaller than the capsule cavity inserts and force the inserts into position, sometimes it is found that in hardening the inserts they become slightly warped, or because of slight burrs there is a tendency for the inserts to scrape the side of the slot in the die roll, forming 2.

chip under the insert, and thus cause it to seat unduly high. In use, as the seal roll is pressed against the die roll, there is a tendency to pound the insert down and flatten the chip so that cutting out is not complete. Particularly with the larger inserts it is frequently convenient to use a slightly larger slot in the die roll and use a retaining screw or other fastener to hold the inserts in position.

Figure 2l shows an otherwise similar capsule cavity insert in a die roll in which the insert is retained in the die roll by a retaining screw 103 threaded into a tapped hole 14W.- in the die roll. A slotted, flat-head machine screw is shown, although other types of fasteners may be used.

Figure 22 shows a short oval capsule forming cavity. The capsule cavity insert 1% is shorter than that used for the long oval capsules and has but a single plug 105 with its associated piston and air ducts under the insert. The insert may have on its lower face an indexing slot 107, as such a slot can be used to hold the insert in position during machining operations. With a short insert it is otherwise difiicult to insure that the insert is properly chucked during the forming operations.

Figure 23 shows a capsule cavity insert for cutting out ellipsoidal capsules. The ellipses of the capsule cavity insert may be cut with an ellipse cutting chuck on an ordinary lathe. As shown, the insert has therein a hollow screw 10% in which the plug 105 fits. By using a hollow screw it is possible to retain the insert in position and still have a centrally located plug for ejecting the capsule. The cylinder, air duct, etc, are as previously described.

A round, cylindrical capsule cavity insert 117 is shown in Figure 24 for the production of spherical capsules. As shown in this modification the insert is a press fit and underneath is the capsule ejector plug 118.

For small spherical capsules or ellipsoidal capsules where there is no danger of binding problems during the release of the capsules, a foraminous area may be used instead of an ejector plug. Tf holes are used there is a tendency for the shell film to be drawn into the hole, but by using a felt plug or other foraminous material the shell film is supported in position during forming, and the air flowing through the porous plug ejects the capsules. As is shown in Figure 25, a cylindrical capsule cavity insert 111 may be used in which there is a tapped hole 112 in which is placed a felt plug 113. Ordinary felt such as is used for oilers in electrical motors may be screwed into the tapped hole.

Whereas it is frequently convenient as shown in Figure 25 to have the top of the felt even with the bottom of the capsule forming cavity in the insert, a certain flexibility in size can be obtained by using a depressed felt lug.

p As shown in Figure 26 a capsule cavity insert 114 has therein a tapped hole 115 in which is threaded a felt plug 116, but the felt plug is shorter and screwed below the bottom of the capsule cavity insert. By changing the depth of the felt plug, the volume of the capsule cavity insert may be varied, permitting an adjustment in the size of the formed capsule.

Another modification is shown in Figure 27 in which the capsule cavity insert 119 is retained in position by an interiorly threaded hollow screw 12!). The interior of this screw has therein a felt plug 121 which functions in the same fashion as described in the modifications shown in Figures 25 and 26.

Figure 28 shows a modification in which the capsule cavity insert 87 is being built up of separate parts. This type of insert is shown in the die roll of Figure 17, and is used in the machine of our application Serial No. 16,554. The die roll 128 has therein inserts 87, which consists of a hollow cylinder 122, the top portion of which forms the cutting out rim. inside of this cylinder is a plug retainer 123. Under the plug retainer and held in position by it is the ejector plug 124. On the ejector plug is an ejector plug rim 125 which slides as a piston in the cylinder formed by the plug retainer 123. In this rim are serrations 126, so that the plug will not form an air-tight seal against the die roll. An air duct 127 leads from the bottom of the cylinder.

Other variations in the size and shape of the capsule cavity inserts may be used to form various sizes and shapes of capsules which may be desired. Round, ellipsoidal, oval, long oval, bottle shaped, dumb-bell shaped, and other forms of capsules can be manufactured, but of course, the symmetrical, long oval, elliptical, and spherical capsules appear to meet with greatest acceptance in the trade.

We claim:

1. An apparatus for forming soft plastic capsules from plastic strips which comprises a die roll comprising substantially cylindrical cavities having rims raised above the general surface of the die roll, ejector plugs, pistons attached to said plugs, and manifolding means whereby air is caused to be evacuated from said cavities during a portion of the cycle and admitted under pressure to said cavities during a portion of said cycle and to simultaneously operate said piston, and retaining means for retaining said ejector plugs in said cavities.

2. An apparatus for forming soft plastic capsules from plastic strips which comprises a die roll having substantially cylindrical cavities therein with rims therefor raised above the general surface of the die roll, an ejector plug, a piston attached to the plug, and plug retainer in each of said cavities, air manifolding means, whereby air may be evacuated from, and admitted under pressure to, each of said cavities during suitable portions of the forming cycle, and also operate the piston and a cooperating substantially cylindrical die roll.

3. A die roll for forming soft plastic capsules from plastic sheet material which comprises a substantially cylindrical die roll blank, a plurality of capsule cavity insert slots in the cylindrical periphery of said die roll blank, at least one capsule ejector piston cylinder in the bottom of each slot, a plurality of capsule ejector plugs, one for each of such cylinders, a capsule ejector piston attached to each of such capsule ejector plugs and slidable inthe capsule ejector piston cylinder, a capsule cavity insert in each of said insert slots, said capsule cavity inserts having in the bottom thereof an opening for each capsule ejector plug, said pistons and plugs fitting loosely in said cylinder and said opening, a cutting out rim on each insert extending above the surface of the cavity die roll blank, the outermost surfaces of such cutting out rims forming portions of a cylindrical surface concentric with the axis of the cavity die roll blank, a manifold means extending from the lower portion of each of said capsule ejector piston cylinders to a valve seat surface of said roll, whereby a vacuum may act on a soft plastic film to position it in the capsule cavity inserts and an air pressure can act to raise the piston, the plugs, and eject the capsules.

4. A die roll for forming soft plastic capsules from plastic sheet material, which comprises a substantially cylindrical die roll blank, having in the cylindrical periphery thereof a series of capsule-forming cavities, each consisting of a raised rim insert fitted into the periphery of said cylindrical roll and having in a recess under said insert at least one ejector plug, said ejector plug having thereon a piston, whereby said plug may be, by air pressure, raised to substantially the top of said cavity, or retracted to form a portion of the bottom of said cavity, a piston cylinder in which said piston slides, a manifolding passage from adjacent one end of said cylinder to a valve surface of said wheel, whereby adjacent valve means may at desired times during the rotation of the roll, cause an increase or reduction in the pressure in said cylinder, thereby actuating said piston and said plug.

5. A capsule conveyor system comprising a shield adapted to cover at least a portion of a capsule forming die roll, means for causing the release of the capsules from the die roll within this shield, and an air jet of high pressure centrally located at a lower portion of said shield, and a larger source of lower pressure air, pointing towards a discharge duct, whereby capsules released within this shield will be picked up by the combined air blasts and propelled towards said discharge duct, which discharge duct may be directed in a selected direction.

6. A capsule conveyor system comprising a shield adapted to cover at least a portion of a capsule forming die roll, means for causing the release of the capsules from the die roll within this shield, and at least one air jet at the lower portion of said shield, directed towards a discharge duct, whereby capsules released within the shield are picked up by the air jet and propelled towards and through said discharge duct, being thereby tumbled and agitated.

7. A machine for forming soft plastic capsules comprising a plastic strip oiling means, a plastic strip coater means, a cavity die roll having therein a plurality of capsule forming cavities, a liquid supply means, a powder measuring roll, a powder measuring roll jet cleaning means, a substantially smooth sealing roll contacting said cavity die roll, and an air jet capsule conveyor means, whereby capsule cavities are formed in one side only in one strip only, filled with each of a liquid and a powder, have thereto applied a plastic covering strip from which the thus enclosed capsule contents may be cut out and permitted to assume a desired configuration.

8. A capsule-forming mechanism comprising a power driven oiler roll, adapted to contact a die roll contacting surface of a plastic strip, an oil feed roll contacting said oiler roll, an oil bath positioned to partially surround said oil feed roll, constant level oil supply means therefor, an inside coating roll adapted to contact the surface of a plastic strip which is to form the inside of the capsule, an inside coating feed roll contacting said inside coating roll, and inside coating trough partially surrounding said inside coating feed roll, constant level feed means therefor, drive means adapted to drive both said oiler roll and said inside coating roll, a die roll which comprises a substantially cylindrical die roll blank, having in the cylindrical periphery thereof a series of capsule-forming cavities, each consisting of a raised rim insert fitted into the periphery of said cylindrical roll, ejector plug means, manifold means adapted to operate said ejector plug means, a liquid supply means adapted to supply a liquid filler for the formed plastic capsules, a powder measuring roll comprising measuring chambers coordinated to supply a powder charge to each of the capsule-forming cavities, a powder measuring roll jet cleaning means comprising a high pressure air jet orifice, air pressure supply means, and manifold means surrounding said air pressure jet means whereby particles moved by the said air pressure jet will be released within said manifold means, a vacuum source attached to said manifold means; substantially smooth sealing roll means contacting said die roll adapted to cut geezer? ounpnd seal capsules formed in-said cavities, and an :air

jet-capsule conveyor means adapted to remove the formed capsules from the machine and agitate said capsules.

9. A machine for forming soft plastic capsules comprising a plastic strip oiling means to oil the surface of powder measuring roll, manifolding means to cause the transfer of powder charges from said powder measuring roll into the plastic shells, air jet means to insure that thepowder measuring roll is kept free from agglomerated powderparticles, a substantially smooth sealing roll contacting said'cavity die roli and adapted to cooperate therewith to place in juxtaposition thereto a second plastic strip, and cut out and seal together portions of each striparound each shell, thereby forming capsules, ejecting means to eject the thus formed capsules into an air jet capsule conveyor means which agitates and tumbles capsules supplied thereto as it conveys them to a desired discharge point.

1-0. An apparatus for forming soft plastic capsules from plastic strips which comprises a built-up cavity die roll comprising a die roll blank, slots therein, capsule cavity inserts having rims raised above the general surface of the die roll in said slots, ejector plugs under said inserts, pistons attached to said plugs, and extending through said inserts, and manifolding means to evacuate air from said cavities around said plugs during a portion of the capsule forming cycle and admit air under pressure to said cavities around said plugs during a portion of said cycle and simultaneously to raise and to lower the pistons attached to said plugs.

ll. A cavity die roll for forming soft plastic capsules from plastic strips which comprises a substantially cylindrical die roll blank having a plurality of slots in the periphery thereof, at least one capsule e ector piston cylinder in the bottom of each slot, a plurality of capsule --for saidplug, said pistons and said plugs fitting loosely in said cylinder and said opening, a cutting out rim on each insert extending above the surface of the the roll blank with the outermost surfaces of such cutting out rims forming portions of a cylindrical surface concentric with the axis of the die roll, and a manifold means extending from the lower portion of each of said capsule ejector piston cylinders to a valve surface of said roll, whereby a vacuum may act on a plastic strip to draw it into the capsule cavity inserts, and an air pressure can act to raise the piston, the plugs, and eject the capsules.

12. A cavity die roll for forming soft plastic capsules from plastic strips, which comprises a substantially cylindrical die roll blank having a plurality of slots in the 'periphery thereof, axle means therefor, a plurality of capsule cavity inserts in said slots, ejector means extending through said inserts, and gaseous manifold means whereby said ejector means are controlled, said inserts having a cutting out rim extending around the entire periphery .of the capsule forming cavities and said rim being the same distance from the axis of the die roll at all points.

13. A cavity die roll for forming soft plastic capsules from plastic strips which comprises a substantially cylindrical die roll having a plurality of slots in the periphery thereof, at least one capsule ejector piston cylinder forming a part of the bottom of each slot, a plurality of capsule ejector plugs, one for each of such cylinders, a capsule ejector piston attached to each of such capsule ejector plugs, and slidable in the capsule ejector piston cylinder, capsule cavity inserts having in the bottom thereof openings for said capsule ejector plugs, in each of said insert slots, a cutting out rim on each insert extending above the surface of the die roll blank with the outermost roll, and manifold passages interiorly of the die roll ex- 11 5 tending from-said cylinders to a valve surface of thedie roll.

14. A cavity die roll as set forth in claim 13, in which capsule cavity inserts are retained in the slots in the die roll blank by friction.

15. A cavity die roll as set forth in claim 13, in which the capsule cavity inserts are retained in the slots by positive fastening means.

16. A cavity die roll as set forth in claim 15, in which the fastening means are screws extending through the bottom of the inserts and into the die roll blank.

17. A cavity die roll as set forth in claim 16, in which the fastening screws are hollow and capsule ejector plugs pass through said hollow screws.

18. A cavity die roll as set forth in claim 13, in which the capsule cavity inserts are formed with a positioning slot in each, thereby permitting accurately indexing of said inserts during their manufacture.

19. A cavity die roll for forming soft plastic capsules from plastic strips which comprises a substantially cylindrical die roll blank having a plurality of slots in the periphery thereof, inserts therein having raised cutting out rims extending above the surface of the die roll blank, ejector plugs inside of said inserts, and retainers inside'of said inserts retaining said plugs in position, said plugs loosely fitted inside of and being slidable inside of said retainers, and air operated means to cause said plugs to slide in said retainer during capsule forming operations.

20. A capsule-forming mechanism comprising a power driven oiler roll, adapted to contact a die roll contacting surface of a plastic strip, an oil feed roll contacting said oiler roll, an oil bath positioned to partially surround said oil feed roll, constant level oil supply means therefor, an inside coating roll adapted to contact the surface of said plastic strip which is to form the inside of the capsule, an inside coating feed roll contacting said inside coating roll, an inside coating trough surrounding said inside coating feed roll, constant level feed means therefor, drive means adapted to drive both said oiler roll and said inside coating roll, a die roll which comprises a substantially cylindrical die roll blank, having in the cylindrical periphery thereof a series of slots, each containing a capsule cavity insert, ejector plug means, manifold means adapted to operate said ejector plug means, a liquid supply means adapted to supply a liquid filler for the formed plastic capsules, a powder measuring roll comprising measuring chambers coordinated to supply a powder charge to each of the strip lined capsule-forming inserts, a powder measuring roll jet cleaning means comprising a high pressure air jet orifice, air pressure supply means, and manifold means surrounding said air pressure jet means whereby particles moved by the said air pressure jet will be released within said manifold means, a vacuum source attached to said manifold means; substantially smooth sealing roll means contacting said die roll adapted to cut out and seal capsules formed in said cavities, said manifold means incorporating means to reiease the operating pressures at the time of cut out and seal, means to cause the capsules-and the residual web to follow different paths, and an air jet capsule conveyor means adapted to remove the formed capsules from the machine and agitate said capsules.

21. A machine for manufacturing plastic film capsules which comprises, means for forming a first film of a pressure sealing plastic material, a rotating cavity die roll having therein a plurality of capsule forming cavities, means for feeding said film over said roll, means for reducing the pressure within said cavities to thereby form a series of substantially cup-shaped cavities in said film, means for depositing into the film lined cavities a predetermined portion of a liquid, separate means for depositing in said cavities a premeasured, preshaped, at least partially compacted charge of powder, means for placing a substantially smooth second film of pressure sealing plastic material in juxtaposition to said first film and cutting by pressure the portions from each film surrounding the combined charges and seaiing said portions to each other, and means for ejecting the thus formed capsules and separating the capsules from the residual films.

22. in a machine for forming powder and liquid filled capsules, means to advance a pair of strips of capsule forming sheet material along converging paths into juxtaposition, said means including a single die roll having therein capsule forming cavities arranged circumferentially thereof, a raised rim around each cavity, and ejection means in each of said cavities; means to draw one of said strips into said cavities; a powder measuring roll comprising a plurality of coordinately spaced and shaped tapered charge measuring chambers each of which has at least a portion of its surface of a foraminous material, means for drawing powder into said chambers, means for striking off the powder even with the surface of said measuring roll, thereby forming shaped at least partially precornpacted powder charges, and means for transferring the charges into the strip lined capsule forming cavities; means for continuously and uniformly feeding the liquid contents to said strip lined cavities at a uniform rate just equal to the rate of encapsulation of the liquid; said means to advance comprising also a second cylindrical roll in rolling contact with said rims whereby the portions of the strips of capsule forming materials surrounding the combined charges are simultaneously sealed together and cut out at the line of rolling contact, thereby forming capsules continuously containing independently controlled portions of both a liquid and a powder.

23. The apparatus of claim 12 comprising a threaded fastener for retaining each of said capsule cavity inserts in said slots.

24. In a capsule forming die roll system a cavity die 18 roll having in the periphery a series of slots, a capsule cavity insert in each slot and a threaded retaining means holding said insert in said slot, said retaining means having there through an opening through which film retaining and capsule ejecting gas flow passes.

25. A capsule forming cavity die roll comprising a substantially cylindrical die roll having a plurality of slots, a capsule cavity insert in each of said slots, a threaded retaining screw fastening said insert in said slot, and an ejecting plug passing coaxially through said screw, and an ejecting air operated piston attached to said plug.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,160,278 Gray et a1. Nov. 16, 1915 2,181,487 Khuen-Kryk Nov. 28, 1939 2,318,718 Scherer May 11, 1943 2,323,581 Weckesser July 6, 1943 2,387,747 Cowley Oct. 30, 1945 2,632,086 Barnet June 29, 1954 

